The invention concerns a machine for dressing the edges and outer surfaces of flat workpieces, including a machine frame with a workpiece support surface and at least one dressing head with a work tool carrier, which dressing head is supported on the machine frame for rotation about a first axis perpendicular to the workpiece support surface and is driven by means of a drive and carries at least two work tools, each of which work tools is rotatably supported on the work tool carrier for rotation about a second axis eccentric to the first axis and perpendicular to the workpiece support surface and is drivingly connected with a planetary gear in driving engagement with a sun gear fixed to the frame and coaxial with the first axis, so that the rotating work tool carrier defines a circle of influence of the work tool.
A machine of the previously mentioned type is known for example from DE 103 38 682 A1. The overlapping of the rotational movement of the work tool carrier and the compelled rotational movement of the work tool with a higher rotational speed of the work tool in comparison to the rotational speed of the work tool carrier makes possible in this mechanism a high cutting capacity of the work tool and therewith an effective dressing of the workpiece. In the case of the machine known from DE 103 38 682 A1 several disc-shaped grinding or dressing heads are provided which are arranged in two rows perpendicular to the movement direction of the workpieces and following one another in the feed direction of the workpieces, with the two grinding head rows being displaced from one another perpendicularly to the movement direction of the workpieces so that the grinding heads of one row—as seen in the movement direction of the workpieces—close the gaps between the grinding heads of the other row. Accordingly, it is assured that the entire working width of the machine is covered by the grinding work tools, however the machine requires a relatively large amount of space in the advancement direction of the workpieces.